Has anyone ever encountered a situation where a sentence pattern didn't unfold the way you thought, and it was due to the conflict between two or more sentence patterns?  I was thinking I understood "qilái" sort of, but what if you added "bǐ"? For example:

It's really hard to fly an airplane

fēijī fēi qìlái hén nán

It's hard to ride a bike

zìxíngchē zuò qìlái hén nán

It's hard to ride a bike, but even harder to fly an airplane.

zìxíngchē zuò qìlái hén nán bǐ fēijī fēi qìlái hén nán

No doubt there's plenty wrong with my example, but hopefully, the point is illustrated enough.

I guess i'm not quite clear when,  as a general set of grammar rules, when certain sentence patterns take precedent. 

Yes, the answer is the usual "it depends" and "it depends on the context of what you're trying to say", but I guess I was wondering about specific examples of when this occurs, or really more interestingly, what are the exceptions to the rules. Maybe there should be a series of Qing Wens to explain what happens when sentence patterns collide, and which sentence pattern takes precedent over another and when.